Electrically operated time switch clock



Jan. 14, 1964 D. ROSE ELECTRICALLY OPERATED TIME SWITCH CLOCK Filed March 26, 1962 5 Sheets-Sheet l R OE .MS W0 man D m. N 0 D ATTORNEYS Jan. 14, 1964 D. ROSE 3,118,028

ELECTRICALLY OPERATED TIME SWITCH CLOCK Filed March 26, 1962 5 Sheets-Sheet 2 INVENTOR DONAL D ROSE ATTORNEY/5' Jan. 14, 1964 D, ROSE 3,118,028

ELECTRICALLY OPERATED TIME SWITCH CLOCK Filed March 26, 1962 3 Sheets-Shea?I 5 F/GJJ -`-"I INVENTOR DONALD vF0335 BY M ATTORNEYS United States Patent O 3,115,02S ELECTRECALLY PERATED TIME SWETCH CLOCK Donald Rose, ltayton, Ghia, assigner to Water Reiining Company, lne., Middletown, (Ehio, a corporation of (Ohio Filed Mar. 26, i962, Ser. No. liZZQ it) Claims. (Cl. Zilli-33) This invention relates to an improved electrically operated timer and its actuation of switches.

An object of the invention is to provide a first electric clock motor to solely drive an hour hand which trggers as desired the actuation of a second drive motor to periodically drive a cam disc operator for operating switches.

Another object is to provide for a periodically driven cam disc which controls the operation of time switches and to provide ease of setting the time for operation of the cam disc.

A further object of the invention is to provide in the cam disc circular cam areas for operation of switches with such areas having adjustable length slots therein for the switch actuation.

A still further object of the invention is to provide for manual push button actuation of the cam disc for selectively setting into operation the drive of the cam disc by an electric motor.

Yet a further object of the invention is to provi-de adjustable positionable cam slot sector pieces for a cam disc to easily vary the slot length thereof for switch actuation by such slots for desired periods of rotation of the cam disc.

These together with other objects and advantages which become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and it which;

FIG. l is a front View of the electrically operated time switches showing the regeneration time set disc, the 24 hour hand therebehind and the manual operated push button;

FIG. 2 is a top plan view of PEG. l with the top lid removed to show the day star wheel;

FIG. 3 is an exploded View of the 24 hour hand, the day of the week star wheel dogged thereby and the 24 hour clock drive motor and gearing;

`F'lG. 4 is an exploded View showing the two hour cam discs for operating switches, two hour cam disc drive motor and gearing and 24 hour clock and drive gearing in phantom;

FlG. 5 is a front elevational View of the two hour cam disc with its adjustable cam slots on an enlarged scale;

FlG. 6 is a rear elevational view of the two hour cam disc of FIG. 5 showing also the drive gearing;

FG. 7 is a top plan view of the two hour cam shown in FIG. 5;

PIG. 8 is a sectional view on line 8 8 of FIG. 5 of the adjustable cam slot on an enlarged scale;

FIG. 9 is a fragmentary top plan view on an enlarged scale of the day star wheel and its cam and two hour motor switch about to be actuated by an in do-wn position day pin and cam slot in two hour cam;

FIG. l() is a view similar to FlG. 9 with the day star wheel having just been dogged so that its down day pin actuates the two hour motor switch to on position and the two hour cam having rotated so its cam slot holds two hour motor switch in on position;

FlG. 11 is a sectional view of the day star wheel, a down day pin and the cam operated thereby on line ill-*l1 of FIG. 9;

llg Patented dan. 14, 19t-54 ICC FIG. 12 is a front elevational view of the cam operated by the star wheel down day pin and the two hour motor switch arm operated by a pin on the cam;

FIG. 13 is an enlarged fragmentary top plan View of the normally off micro switch for the two hour cam drive motor;

FIG. 14 is an enlarge-d fragmentary top plan view of a normally off two hour cam disc operated micro switch in normally off position;

FiG. l5 is a rear elevational view of the two hour cam disc and the micro switches operated thereby; and

FIG. 16 is a front plan View of the manually operated push button for operating the two hour cam disc with a portion of the front of the cam disc broken away to show the pins.

The electric timer is generally indicated at lil and the mechanism is fully contained within a housing l1 of suitable molded plastic of generally overall square boxlike shape with a circular boss l2 at the front which has a circular recess 12a therein with a reduced diameter cavity 12b extending into the housing to receive the cam disc to be described and a circular dial-like face 13 having twenty four hour day indicia markings 13a in contrasting colors Ifor am. and p.m. The face l has a transparent portion so that a portion of an hour hand 24 therebehind may be seen. The face 13 seats on a shoulder adjacent the outer edge of boss l2 and is easily rotatable therein by an annular center knurled outwardly protruding por tion i3b. The `face :t3 is held in by a removable retainer i4 secured by a screw 14a which threads into the housing il. An indicia marking iS in engraved into the housing or otherwise applied at its upper portion in the circular boss as a reference marking for setting the face i3 for desired time of switch actuation as will be more fully discussed. The reduced diameter recess 12b extending 'itc the housing il from the circular boss ft2 terminates in a suitable vertical partition or wall 16, see portion in FIGURES 2 and l5, which serves as a mounting for the motors, a star wheel and a manual actuating mechanism to be described. The upper part of the housing il has a recess lla which terminates at its bottom in a horizontmly extending mounting shelf-like portion i7 having a day of the week indicia marking 17a thereon. A suitable easily removal lid i3 closes the top recess lla. A suitable moulded recess i9, see FIGURES 13, 14 and 15, extends into the back of the housing below the horizontal shelf i7 to receive the micro switches and their terminal connections, to be described. A removable back plate 2t) is secured by screws 2tlg to the track of housing il.

A centrally disposed drive shaft assembly for driving a twenty four hour hand and rotatably mounting a two hour cam disc, both to be described, is indicated at 2l. This shaft assembly is mounted at its rear journal end 21a, see FIG. 4, in a suitable bearing bushing (not shown) extending through and carried by the partition le. This shaft assembly 2i has an enlarged journal portion 2lb having a peripheral recess .lc therein to receive a conventional snap over C-shaped retainer disc (not shown) and a forward journal portion 2id with an internally threaded recessed end 21e to receive a retaining screw 22. The rear journal end 21a is likewise provided with a recessed threaded end Zlf to receive a suitable retaining screw whose head will provide a stop against the bearing bushing (not shown) to hold the shaft assembly mounted in the partition i6.

The shaft assembly 21 is driven by a twenty four hour clock motor 22 having a gear box 22a with apertured mounting ears 2lb which receive mounting screws to secure the motor clock motor within the rear of housing ll and to partition 16. A drive shaft 22C powered by the gear box 22a extends through an aperture in partition i6 positioned to the right of shaft assembly 2l as viewed from the front. Mounted on the end of shaft 22C is a drive pinion 23 which meshes with a larger gear 2de secured to shaft assembly 2l whereby it is rotated in a clochwise direction once each 24 hour period. A twenty-four hour hand 24 has a central apertured knurled mounting hub portion 24a which is received on the journaled forward end 2id and heid thereon by the securing screw 22 and an internal friction coiled spring (not shown) within the hub whereby the hand Zd may be manually adjustably rotated in the clockwise direction to set the same. hand 24 has a transversely and rearwardly projecting lug portion 2411 which rotates one step, once each day, a star wheel 25. The star wheel 25 is received on' a vertically extending post 26 projecting up from partition 16 and the horizontal door 17 of the housing, see FiG. 2, and held thereon by a C-shaped spring disc retainer 26a. The star wheel 25 is shown with seven radially projecting spaced apart fingers 25a which are bifurcated and apertured vertically to receive settable down and up pins 25'). One finger is provided for each day of the week or six ingers could be provided and an every other day setting could be utilized. The lug portion 24h on hand 2d rotates once each twenty four hours and strikes one of the ngers of the star wheel to rotate the star wheel one step. A leaf spring Z7 is secured to a wall of upper recess 1in of the housing by a screw 27a and its end 27h is bent at a right angle so as to springly engage between the fingers 25a and hold the star wheel in a set position when not being dogged. The purpose ot the star wheel 25 and its selected down projecting pins 25h will be describe-z Mounted on the horizontal lioor [l of the housing il is a first cam assembly 2S on a vertical pivot post 28a, see FGURES 9, l() and 12, received in vertical aligned apertures in iioor 17 and door i90 of recess 19 shown in FIG. 15. This cam assembly 7.8, as best shown in FIGURES 9, and 12, is a molded unit having a triangular body Zb, a horizontally projecting finger 28e with a hooked portion 28C extending under the fingers a so as to be engaged and rotated by a down pin 25h as it rotates in a clockwise direction as viewed from the top. Projecting vertically downward from body portion 2gb is a pin 28d which serves to swing clockwise an actuating finger of a :first micro switch, to be described, when the cam 2S is rotated by one of the down pins 25h as shown. The star wheel 25 and its actuation of first cam assembly 28 holds switch 29 closed for about thirty minutes while it is only necessary for about two minutes as the cam disc control will hold the switch Z9 closed for about degrees of rotation as will be explained.

The lirst micro switch 29 is a normally ott switch and closes when in on position and completes an energizing circuit to a two hour cam drive clock motor 30. The switch 29 is or conventional construction and is shown in FIG. 13. It has an insulated mounting and terminal strip 29a to which is rivetted an L-shaped mounting bracket 29]; having in the outwardly projecting portion an elongated aperture 2/9c therethrough adjacent its outer end and extending parallel to the mounting strip 29a and an elongated recess 29d in the inner face thereof intermediate the aperture and mounting strip and parallel to the mounting strip 29a. Received over the projecting portion or" bracket 2% is a specially formed conductor leaf spring member 29e of elongated annular shape with a central tongue portion 29j bent in arc shape and integral with a contact end 29g carrying contact button 29h. The free end of arcuately bent outwardly finger 2% is received in the recess 29a' of the bracket. An actuating linger 291' is specially shaped at its mounting end. lt has an offset portion 29]' received in slot 29C in a pivotal mann-er and an inner end 2li/c bent to extend generally parallel to its main portion and received in the adjacent end of annular conductive spring member 29e. The actuating end oi actuating finger 291' is indicated at 293. The other terminal of switch is a generally Z-shaped bracket 23m which rivetted to the mounting strip 29a adjacent the end movable Contact 29g. Terminal L-shaped members Zln and 29p are respectively secured by the rivets to the mounting strip 29a opposite the brackets 291) and 29m to which they are electrically connected by the respective securing rivets. In FIG. 13, switch 29 is shown in normally oi position but when the actuating end of finger 291 is swung clockwise initially by the pin 28d on cam assembly Z5, the contact spring 29e shifts to contact the terminal 29m with which it completes a circuit to the two hour cam motor Sti to energize the same. A two hour cam disc 3l which is driven by the motor Sli will hold the outer end 29! oi actuating finger 291' in the clockwise urged attitude whereupon the switch 29 is held closed to cause rotation of the cam disc as will be described.

The two hour cam drive motor 3l) is of like construction to motor 22 and has a gear box Sdn, mounting ears by which the motor is mounted in the rear of housing l1 to the partition le and its drive shaft 39C projects through an aperture in partition 16 positioned to the left of the central shaft assembly 2l as viewed from the iront of the timer. A drive pinion 39d is xed to the outer end of drive shaft tlc.

The two hour cam disc 31 is built up about and held clamped together by a central hub 32 which is received over the enlarged centrally disposed journal portion 2lb for free rotation thereon within the cavity iZb in housing iii so that it positions the cam disc 31 in closely spaced relationship forward of the front face of partition 16. A C-shaped spring retainer disc (not shown) is received in the peripheral recess Zic on the shaft assembly adjacent the front end of the hub 32 to hold the cam disc in position on shaft assembly 2l. Starting from the rear of the cam disc 3i., as shown in FIG. 7, there is mounted on hub 32, a drive gear 33, an annular rear spacer 3d, a main body 35 having an integral iront annular boss 35a, adjustable cam slot section pieces 35 and 37, a disc 3S with external teet 38a on one half the outer circular portion thereof. When the cam disc 3l is in position on the shaft assembly 2l, the drive gear 33 thereof will mesh with the drive pinion 3de', see FGURES 4 and 6, of the two hour clock drive motor 3d.

The main body 35 of the two hour cam disc 31 has three cam areas therein which starting from the outside are at di, d2 and Cam area il which is on the outer portion includes a sector slot dis extending from dia to @lb where wall portions of the slot in main body 35 extend generally radially to deiine the ends of the slot of cam area 41. Also in cam area iii is the corresponding peripheral back face le of the main body disc 35 extending from 41h, sce FiG. 6, clockwise to 4in. A guard for the bottom of slot di is indicated at dit!! and is made up of a transversely and forwardly projecting piece 43d and a diagonal piece did" joining the outer end of lld and the portion indicated at lill). This cam area di made up of slot Lils between 4in and 41h and the baclt face portion llc cooperates with the end portion 2.9i of the actuating iinser 2n oi the `first switch 29. This switch 2% is first actuated to closed position, as above described, by pin 28a' on cam 28 moving the iinger 291', see PEG. 9, whereupon the two hour cam motor Sti is energized and the cam 35 and its main body 3l is rotated counter clockwise, see FIG. il), and the end 29Z of the cam finger 2.9i rides on the back surface cam portion sie to hold the switch contact 2?!! closed against contact Z3. see PEG. 13. Upon completion ot one rotation of cam 35, in say a two hour period, the `inger 29! drops into a slot ills between 21a and di of cam area dit and the nger swings counter cioclcwise to open the switch contacts and breaks the energizing circut to motor Sii.

rthe second cam area 4Z on cam disc Si., more specifcaliv on the main body 35 of the cam disc will now be described. This comprises in main body 31, see Fifi" URES 5 and 6, an arcuate s1ot42s extending from radially extending shoulder 42a to adjustable cam slot sector piece 36 at 36b thereon. The rest of cam area 42 in the arcuate back surface area 42C in arcuate alignment with the slot 42s.

The third cam area 43 on cam disc 3l, more specifically on the main body 35 of the cam disc is now described. Reference to FIGURES 5 and 6 shows that this comprises in the main body 3l an arcuate slot 43s extending from 43a to the 37b on adjustable cam slot sector piece 37 and a back surface area 43C in arcuate alignment with the slot 43s. In use the ends of the actuating ngers 441' and 451' of micro switches, such as shown in FIGURE 14 at 44 and 45, rides on their respective cam areas 42 and 43 and upon dropping into slots 42s and 43s such fingers swing and close their' switch contacts to complete circuits as desired. When the end of the actuating finger rides on the back face cam area 42e and 43e respectively, the fingers 441' and 451' are swung to hold their switch contacts open. In FIG. l5 the actuating iingers 441' and 451' of these micro switches 44 and 45 are shown projecting in suitable slots 219s in wall t6 adjacent the recess 19 in the housing lll.

Each of the lengths of slots 42s and 43s may be adjusted by use of the respective adjustable earn slot sector pieces 36 and 37. In the main body 35 of the cam disc 3l there is formed an arcuate guide groove 46 of equal radial distance from the center of the disc shaped main body 35. The sector pieces 36 and 37 are generally alike. Sector piece 37 has a pie-like shaped main 1oody 37C, see the broken line outline in FIGURES 5, 6 and 8, and has an inner arcuate edge 37d which rides against the outside ot' circular boss 35a on main body 3S while the outer arcuate edge terminates at 37e spaced in from the outer peripheral edge of main body 35'. Extending transversely and integrally with the main body 37C from one edge of the sector is an arcuate boss 37]c which rides in guide groove 46 in main body 3S. A stop lug 37g projects transversely from the main body 37e of sector piece 37 adjacent but radially inward from the lug 37j and this stop 37g rides in the adjacent arcuate cani slot portion 43s and strikes against the adjacent end of slot 43s to limit the travel ot the sector piece 37 in one direction. The travel of the sector piece 37 in its opposite direction is limited by a pin 47 against which the edge 37h of the sector piece will strike. One means ot moving the sector piece 37 to an adjusted position to change the length of slot 43s is a knurled gear 48 which is pivotally mounted adjacent toothed disc 38 on a pivot post 4811 projecting from sector piece 37 and secured thereon by a C-shaped spring washer. The teeth or knurling 4&1 of gear 48 mesh with the external teeth on disc By rotating the gear 43 by ones lingers, the sector plate 37 is adjustably positioned. A suitable indicia scale 49 is provided on the front adjacent face of member 35 and a reference arrow Sil is provided on the sector piece 37. The markings here shown are in minutes and they are here labeled as for Backwash when the timer is used with an automatic water softener'.

The adjustable cam slot sector piece 36 is of like construction but its transverse integral stop rides in cam slot 42s and is positioned radially outward of the lug Soi of piece 36 which rides in guide groove 46. A stop pin 47:1 is provided to limit the travel of sector piece 36 in one direction of travel.

The adjustable cam slot sector piece 36 cooperates with cam slot 42s to adjust its length. The cam actuating area 42 is used to control the actuating finger 441' of micro switch 44. Suitable indicia and minute markings are here shown as for a Fast Rinse of an automatic water softener. The micro switches 44 and 45 each control a solenoid which operates a respective valve mechanism in an automatic water softener. However, the timer may be used for other control systems. It will be noted that micro switch 44 and its like switch 45 whose actuating nger 45! shown in FIGURE 15 has contacts arranged somewhat the reverse of switch 29. In switch 29 when the actuating lever is swung clockwise, the contacts make its complete circuit. In switch 44, here illustrated, swinging of the actuating lever 441' clockwise breaks the contacts to olic and when swung counter clockwise the contacts are on.

A manual push button operator for initially rotating cam disc 3i is shown in FIG. 16. rlhe initial rotation of the cam disc 3l is just sui'iicient to rotate it so its slot ls permits the end 29! oi actuating finger 291' to swing so as to close the contacts of switch 29 and energize the power circuit to the two hour cam motor 22 to rotate cam disc Slt for the balance of one rotation whereby the actuating ngers of switches 44 and 45 are made to operate their respective switches in proper selected relation. For example, when the timer is used with an automatic water softener one push on push button will move the cam disc 3l to make the cam disc run through a complete rotation, i.e., a complete cycle of the water softener.

Two pushes on the button 55 will rotate the cam disc 35 a sufficient amount to initiate, for example, a short backwash and a full brine and fast rinse in an automatic water softener to which the timer is connected. In other words, the initial part of a full cycle is passed over all at once.

rl'hree pushes on the button 5S will rotate the cam disc 31 so as to position the cam disc 31 for a short brine and a fast rinse wherein a prior part of the complete cycle is passed over all at once.

The push button 55 and how it imparts stepped limited rotation to cam disc 31 will now be described. T he push button :S5 is mounted in the housing ll so as to protrude to the outside lett as viewed from the front of the timer thereof. The button 5S is reciprocably mounted in the housing il and has a plate member 55a with an elongated slot 55!) therein. Plate portion 55a rides adjacent and parallel to the iront face oi' partition llo adjacent the lower portion of the housing and the slot 51: thereof receives a pin 56 projecting out from the front face of wall it?. The push button 55 is held biased in out position by a tension spring 57 anchored at one end to the housing partition lo by a screw 57a and at its other end it connects with the plate 5511 of the push button.

Three pins 5S, 59, and 6d arcuately spaced apart and equally distant from the center of main body 3S project from the adjacent rear face of the main body 3S. These pins are so positioned that pin 58 is adjacent plate 55a when the cam disc 3l. is at position of rest, i.e., switch 29 is open. A ilat spring pusher member SSc is attached to the plate 55a of the push button and is shaped at its unattached end with a right angle otIset portion 55d to engage pin 53. Thus, when the push button is pushed in once, as stated above, the cam disc 3l. is rotated counter clockwise an arcuate amount as indicated by the broken line position of plate 55a and pin 58. This action, as stated above to initiate a complete cycle, moves actuating arm 291' ot micro switch 2% out of slot 41s and the switch contacts close to complete an energizing circuit to motor 3) to drive cam disc 3i the balance of one complete turn whereupon the end 2Q] of actuating arm 291' drops into slot ils and opens the contacts of switch 29 to stop motor 36. The push button when pushed two times will catch pin 59 on the second push as pin 59 has moved to take up the prior position ot pin 55S adjacent pusher 55d on the first push and, as explained above, a short backwash and full brine and fast rinse cycle is initiated. On the third push on button 55, in 60 is in line with pusher 55d and it is pushed to rotate the cam disc 3l so as to carry out a short brine and fast rinse cycle, as explained above.

While not shown, ilexible terminal connectors for the terminals or switches 29, 44 and 45 and the motors 22 and 3i? are easily lead to terminal connectors (not shown) on the removable back Ztl of the housing 11. In the use of the timer, electrical power connections may be lead to salopes the terminals leading to the motor Sti to initiate drive of the cam disc 3l from a remote position such as from an over iiow indicator of a water softener brine tank. in the setting of the timer, the particular days oi actuation are selected by pushing down the desired day buttons 25!) on star wheel day of the week as marked on the lug 25a carrying the button is positioned adjacent the Day arrow 17d on shelf 17 of the housing il. The time of day desired for actuation of the two hour cam disc 3i is set by just rotating the face or disc E3 to bring the hour desired adjacent the arrow l5 on the housing. After the twentyfour hour hand 24- is set for the time orf day by rotating same as it appears behind a transparent circular part of the face 13.

As can be seen there is provided in this tim-er a very small load on the twenty-tour hour clock motor ZZ and its gear train to rotate hand 2li once each twentydour hours to in turn rotate the star wheel 25 one step per twenty-four hour day. Star wheel 25 turns with little resistance and therefore on the continuously running motor 22 there is little load. By this means very accurate time and proficient performance is realized. The periodicaily energized two hour, for exampie, cam motor is the motor which carries the most load. The cam disc operates the micro switches such as i4 and t5 and while there is not a great amount ot load on the niotor 3d, there is more than on motor The accuracy required here with the drive of earn disc 3l is not so great as with the twenty-four hour timer.

While two switches 44 and i5 have been illustrated, it would be possible to enlarge the timer to accommodate additional cani areas like areas d?. and on the cam disc Sil to accommodate respectively more switches for use with various circuits.

A highly advantageous feature of this timer is the ease and accuracy of adjusting the length of cani slots 42s and 43s by rneans of the respective adjustable cam slot sector pieces 345 and 3"?. The gear drive adjustment ot these sector pieces makes for ease and accuracy of posi- .tioning of the same. While gear drive movement of the sector pieces 36 and 37 is illustrated other adjusting means may be used.

I claim as my invention:

1. An electric timer for opening and closing switches, comprising, in combination, a housing having mounted therein, a tirst and at least a second switch, each of said switches having a pivotal actuating finger, a first motor for driving continuously a hand making one revolution every twenty four hours, a second motor for driving7 periodically a period cam disc, a period cam disc driven by said second motor, a day of the week star wheel having individual day positionable pins therein, a twenty four hour hand driven by said lirst motor and having a portion thereon positioned for rotating said star wheel in one day advance position per each twenty four hours rotation, pivotal cam means adjacent said star wheel and pivoted by a positioned pin of said star wheel, said cam `means having an arm thereon for engaging the actuating linger of said first switch positioned thereadjacent to close and open the same, said first switch when closed being connected to energize said second motor, said period cam disc having a first slot therein within which the end of said first switch linger positioned thereadja- -Y cent rests in open position of its switch when not actuated iby said arm `on the pivotal cam means therefor and at least a second slot in said cam disc positioned in radial distance `from the first slot for receiving the actuatingy tinger of said second switch positioned thereadjacent for actuation to one position, said fingers ot said switches .riding on the respective adjacent portions in said cam disc to said slots when not resting in said slots whereby said switches are actuated to an opposite position, said first switch being held closed after said initial closure by 4said first switch finger riding on said disc portion for I energizing said second motor whereupon to rotate said period cam disc one revolution.

2. An electric timer for opening and closing Switches according to claim 1 including a twenty four hour annular disc mounted in said housing adjacent said twenty four hour hand and manually rotatable in said housing for setting.

3. An electric timer for opening and closing switches according to claim 1 wherein said twenty four hour hand is mounted for drive by said twentyiour hour motor and for manual setting and including a twenty four hour annular disc mounted in said housing adjacent said twenty four hour hand and manually rotatable in said housing for setting.

4. An electric timer tor opening and closing switches according to claim l including a manually positionablc actuating member mounted in said housing adjacent said period cam and actuatable from outside the housing for initiating rotation of said period cam disc, said period cam disc having spaced apart pins arranged arcuately thereon for sequential engagement by said manual actuating member whereupon said period cam disc is rotated a selected amount and said first switch actuating ringer is actuated to close said rst switch whereupon said second motor, is energized to drive said period cam disc and said cam disc is driven thereby for the balance of a rotation to actuate said second switch.

5. An electric timer according to claim l wherein said period cam disc has means movably attached thereto and with a portion thereof slidafble at one end of said second slot for adjusting the eiiective length of the slot within which said second switch actuating linger extends.

`6. An electric timer for opening and closing switches, comprising, in combination, a support means having mounted therein, a rst and at least a second switch, each of said switches having actuating means attached thereto, a rst electric motor for driving continuously a hand making one revolution every twenty `four hours, a second electric motor for driving periodically a period cam disc, a period cam disc driven by said second motor, a star wheel having individual day positionable pins therein, a twenty four hour hand driven by said first motor and having a Aportion thereon positioned for rotating said star wheel in one day advance position per each twenty tour hours rotation, pivotal carri means adjacent said star wheel and pivoted by a positioned pin of said starwheel, said cam Jeans having an arm thereon for engaging the actuating means of said lirst switch positioned thereadjacent to move it to close said lirst switch, said first switch when closed being connected to energize said second motor, said period cam disc having a first slot therein within which said irst switch actuating means positioned thcreadjacent rests in open position of its switch when not actuated by said arm on the pivotal earn means therefor and at least a second slot in said period cam disc positioned in spaced radial distance from the rst slot for receiving the actuating means of said second switch positioned thereadjacent for actuation to one position, said means for actuating said switches riding on the respective adjacent portions in said cam disc to said slots when not resting in said slots wherelhy said switches are actuated to an opposite position, said lirst switch being held closed after said initial closure for energizing said second motor by said lirst switch actuating means riding on said cam disc portion whereby said second motor rotates said period cam discone revolution.

7. An electric timer according to claim 6 wherein said period cani disc has means movably attached thereto ant with a portion thereof slidable at one end of said second slot for adjusting the elie'ctive length of the slot within which said actuating means extends for actuating the second switci 8. ln an electric tirner having a motor driven period cam disc for cooperation with actuating arms of electrical switches, a period cam disc comprising a main disc portion having an axis therethrough, a drive gear attached to one face of said r ain disc with its axis in alignment with that of the main disc, a series of concentrieally arranged arcuate cam slots in said main disc disposed at varying radial distances from the center of said main disc, a centra! circular hub extending transverseiy from tne other `face of said main disc, a positioneble cam slot sector piece mounted for movement on said other face of said main disc and having an inner :arcuate portion siidably abutting against an adjacent peripheral circular portion of said hub and a ltransversely extending portion thereon slidafoly received in one of said arcuate cam slots, said sector piece having means thereon for holding the seme adjustably positioned on said main disc whereby the effective length of the slot with which it cooperates may be varied.

9. A period com disc for an electric timer according to claim 8 including n disc attached to said hub and having a portieri thereof overlying a portion of the adjacent sector piece and having a toot-hed exterior 'arcuate portion thereon `adjacent said sector piece and wherein said means for positioning and holding the sector piece in adjust-ed position with respect to the main disc and its slot includes a knurled gear member pivotally mounted on said sector piece adjacent toothed sector portion on said dise adjacent said hub and having a portion of the knuried portion of the gear meshing with said tooth portion whereby lhy turning the gear ladjusts the arcuate positioning of said sector piece with respect to the main disc and the cooperating slot for the sector piece.

10. A period cam disc for an electric timer according to ciairn 9 wherein said main disc has an arcuate groove in said opposite [tace thereof concentric with said slots therein and said sector piece overlies a portion of said groove and has a transversely extending arcuate lug thereon slidably received Within said adjacent groove in the main disc.

References Cited in the iile of this patent UNiTED STATES PATENTS 2,078,781 Sprenger et al. Apr. 27, 1937 2,231,663 Sprenger Feb. 11, 1941 2,848,630 lvIcNicol et al Aug. 19, 1958 

8. IN AN ELECTRIC TIMER HAVING A MOTOR DRIVEN PERIOD CAM DISC FOR COOPERATION WITH ACTUATING ARMS OF ELECTRICAL SWITCHES, A PERIOD CAM DISC COMPRISING A MAIN DISC PORTION HAVING AN AXIS THERETHROUGH, A DRIVE GEAR ATTACHED TO ONE FACE OF SAID MAIN DISC WITH ITS AXIS IN ALIGNMENT WITH THAT OF THE MAIN DISC, A SERIES OF CONCENTRICALLY ARRANGED ARCUATE CAM SLOTS IN SAID MAIN DISC DISPOSED AT VARYING RADIAL DISTANCES FROM THE CENTER OF SAID MAIN DISC, A CENTRAL CIRCULAR HUB EXTENDING TRANSVERSELY FROM THE OTHER FACE OF SAID MAIN DISC, A POSITIONABLE CAM SLOT SECTOR PIECE MOUNTED FOR MOVEMENT ON SAID OTHER FACE OF SAID MAIN DISC AND HAVING AN INNER ARCUATE PORTION SLIDABLY ABUTTING AGAINST AN ADJACENT PERIPHERAL CIRCULAR PORTION OF SAID HUB AND A TRANSVERSELY EXTENDING PORTION THEREON SLIDABLY RECEIVED IN ONE OF SAID ARCUATE CAM SLOTS, SAID SECTOR PIECE HAVING MEANS THEREON FOR HOLDING THE SAME ADJUSTABLY POSITIONED ON SAID MAIN DISC WHEREBY THE EFFECTIVE LENGTH OF THE SLOT WITH WHICH IT COOPERATES MAY BE VARIED. 